Spring loaded brake apparatus

The braking system (1) has an actuator (2) which incorporates a piston (8) loaded by a spring (22), made of Belleville washers (32), toward its brake application position. An annular chamber (18) may be filled with fluid under pressure to push the piston against the spring to release the brake. The piston incorporates a pumping piston (41) working in a pump chamber (45) connected to the hydraulic system (4). The piston incorporates an electric motor (34) driving a nut (42) on a non-rotating threaded spindle (44) forming part of the brake actuator rod (47).